This application claims the benefit of Japanese Patent Application No. 2006-258027, filed Sep. 22, 2006, which is incorporated herein by reference.
1. Field of the Invention
Embodiments of the present disclosure relate to an ink-jet ink set.
2. Description of Related Art
To develop a clear, full-color image by using an ink-jet recording method, an ink set composed of a yellow dye ink, a magenta dye ink, and a cyan dye ink may be used.
Printing black information using such an ink set can be performed by mixing three primary color inks. Because the printing costs may become high, the black information may be printed using, as a separate ink in the ink set, a black dye ink, which may be available at relatively low cost.
But, the black dye ink may lack sufficient light fastness, water resistance, and/or ozone resistance. For that reason, a black pigment (e.g., carbon black) that is more light-fast, water resistant, and/or ozone resistant may be used as a colorant of a black dye ink of an ink-jet ink set.
However, as compared with a black dye ink, the black pigment ink may not be sufficient in rub fastness of a printed matter. For example, when the printed matter is touched, e.g., by a finger, the black ink may adhere to the finger. Image quality also may be reduced (e.g., by smearing) when an image is rubbed by a finger and/or between papers.
In addition, where organic pigments or dyes are used, some fading of a color image may be inevitable. If the respective inks fade equally, image quality (e.g., color balance) may be preserved a little. But, because black pigment ink typically fades more slowly than color dye inks, black pigment ink may become unnaturally noticeable in faded color image areas. It has been proposed to use a black pigment (e.g., carbon black) in combination with a black dye (Japanese Patent Application Laid-Open No. H11-349876A).
But, because black dye and color dyes do not fade equally, the problem that a print portion of the black pigment ink becomes unnaturally noticeable from faded color image areas persists. It may be appropriate and/or desired for inks for ink-jet recording to be required to have storage stability and/or water resistance in a recorded image.